ROXY Exceed System for EC-MS

ROXYTMExceed System for EC-MS
The ROXY™ Exceed is a new generation Potentiostat dedicated for on- and off-line coupling of Electrochemistry with Mass Spectrometry (EC-MS). With over 130 peer reviewed scientific publications of its predecessor, the Exceed is the best choice for seamless EC-MS.

On-line Mode
In on-line mode the ROXY Exceed can be used in (a) direct infusion mode, (b) for flow injection analysis, or (c) with any type of LC-MS system, e.g., HDX-MS, top-down or bottom-up LC-MS proteomics.

Off-line Mode
In off-line mode the ROXY Exceed is mainly used for electrochemical synthesis and for the collection of electrochemically generated products.

Over 90% of the worlds existing compounds possess REDOX properties making them either oxidizable or reducible. By injecting your analyte into an electrochemical cell and identifying the reaction products by MS, many of nature’s REDOX reactions can be mimicked (simulated) within seconds without any biological interactions, making on-line EC-MS the technique of choice.

Electrochemistry-MS the technique of choice for fast simulation of any REDOX reactions!
“In-electro” a rapid and much cleaner alternative to costly and time consuming in-vivo, in- vitro, microbial, enzymatic or chemical reactions

EC-MS is the perfect analytical technique for:

  • Fast generation of (drug)metabolites, intermediates, and degradants
  • No interferences with matrix (e.g., cell membranes, microsomes)
  • No need of costly enzymes
  • Direct identification of reaction products including short lived components
  • Substantial time and cost savings compared to chemical or enzymatic reactions
  • Superior MS data: better Id and sequence coverage
  • Easy scale-up for synthesis of mg quantities

Flow Cells
Different electrochemical flow cells are available, e.g., ReactorCell, μ-PrepCell (2.0 and SS), and SynthesisCell, to master the most demanding applications


ReactorCell™ – Universal Starter Cell

  • Flowrate 1-20ul
  • Oxidation / reduction / activation
  • Virtually zero sample adsorption
  • Easy electrode exchange

μ-PrepCell™ 2.0 –  for efficient oxidations

  • Robust and reproducible oxidations (20 -100 μL/min)
  • Fast generation of metabolites, intermediates
  • Large working range (potential)
  • Excellent correlation with metabolic & degradation pathway

μ-PrepCell™ SS – reduction of disulfide bonds in proteins

  • Fast and efficient reduction of   S-S bonds in proteins/peptides
  • Long term stability and reproducibility
  • Reagent free, no interfering DTT, TCEP
  • Superior peptide sequencing and S-S bond assignment

 

Applications

Proteomics

In proteomics and protein chemistry, Electrochemistry (EC) is mainly used for the reduction of disulfide bonds, thereby replacing the use of the often harsh and insufficient chemical reduction (DTT, TCEP).

 

 

 

 

Disulfide bond reduction: replacing interfering chemicals (e.g., DTT, TCEP) by an electrochemical reactor cell used on-line with LC/MS)

 

Online HPLC/EC/MS analysis of a mixture of insulin (m/z 1147.7379) and somatostatin (m/z 819.3654).  The overlays in A and B show the m/z traces of the non-reduced intact peptide with the  μ-PrepCell “OFF” (main peak) and the almost fully reduced peptide with μ-PrepCell “ON” with reduction efficiencies of 95 and 97%.

 

Drug Metabolism

EC-MS has been applied successfully for fast prediction and mimicking of oxidative drug metabolism (“in-electro“ vs. in-vivo or in- vitro). The metabolites are formed instantaneously in the electrochemical cell (biomimetic oxidation), mimicking the enzymatic biotransformation of the Cytochrome P450 reactions of the liver (Phase I reaction) including adduct formation (Phase II reactions). Compared to conventional in-vivo methods (e.g., rodents, humans) or invitro methods (e.g., microsomes), considerable time and cost savings have been published.

 

Amiodarone m/z 646 with its major oxidation products (metabolites), m/z 618, 590, 520, 492

Electrochemical Synthesis

In most areas of drug discovery & development and for degradation studies of pharmaceuticals/ xenobiotics in environment, there is a need for reference materials (i.e., metabolites, degradants, etc.). Scale-up to mg quantities is required for structural identification of these products by MS and NMR, and for subsequent toxicology studies. Conventional strategies such as wet chemistry or enzymatic approaches are time consuming, cumbersome, expensive and often unsuccessful. Electrochemical synthesis is a purely instrumental technique capable of rapid synthesis of mg quantities in less than 1 hour.

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